"I have sought and received Hungarian legal advice from Hungarian citizenship law experts.

"I have sought and received Polish legal advice from Hungarian citizenship law experts.

"I have sought and received Australian legal advice."

Not 'formal position' to pursue Frydenberg

Opposition frontbencher Mark Butler, meanwhile, said it was not the party's "formal position" to pursue Mr Frydenberg on the issue.

"Labor proposed a non-partisan list of MPs to be referred to the High Court for consideration of their eligibility based on citizenship and Josh Frydenberg was not on that list," he said.

"The formal position is reflected in the motion we presented to the Parliament earlier this week, that is what we think should go before the High Court.

"It was drafted by the Labor Party, including Mark Dreyfus and the crossbench MPs, all five of them, and it did not include Josh Frydenberg."

Last week, Labor frontbencher Ed Husic indicated he was uncomfortable with his party's line of questioning.

"If we get to the point where we're pursuing people who were stateless and escaping one of the most horrific episodes in human history, well, I'll be interested in seeing how far we pursue that."

Opposition MP Michael Danby also weighed in, telling the Australian Jewish News Mr Dreyfus' approach was "just political tactics and not cognisant of the wider political, historical and ethical issues".